Scientists say PFAS health limit for Michigan’s drinking water may be too high

Michigan residents watched the statewide testing for PFAS chemicals in drinking water during 2018 while hearing messages that health risks were minimal if the results stayed below a certain level.

Now, a panel of scientists say, that level – accepted at 70 parts per trillion (ppt) for two types of PFAS – likely is too high.

That benchmark “may not provide a sufficient margin of safety,” said Dr. David Savitz, professor of epidemiology at Brown University and the chief scientific consultant for Michigan’s PFAS initiative.

Savitz released that finding on Tuesday during a media presentation that coincided with distribution of a report requested earlier this year by Gov. Rick Snyder amid escalating concerns about the per- and polyfluorinated chemicals in Michigan waterways and public drinking water sources.

Savitz collaborated with five other scientists who study the so-called “forever chemicals” across the U.S., producing “Scientific Evidence and Recommendations for Managing PFAS Contamination in Michigan” as a guideline for state policy. The chemicals are linked to cancer, thyroid disorders and neurodevelopment problems.

The timing of the report coincided with a vote by the state House of Representatives on a passed state Senate bill that did not consider the science: Senate Bill 1244 requires PFAS cleanup standards to be based on an outdated database of toxicity criteria, and some say the lame-duck proposal would lock in existing cleanup criteria even as understanding of the chemicals and their dangers to public health continue to evolve.

The Legislature received a copy of the report, and Snyder said through a spokesperson that he hopes elected officials consider the recommendations.

“He does agree that thorough and deliberative reviews that include the Legislature should be taken up as soon as possible next year to ensure the proper standards are set and the appropriate policies to enact those standards are put into place,” said Ari Adler in an email.

A spokesperson for Gov.-elect Gretchen Whitmer said her transition team will evaluate the report, among other information on the chemicals, and make a recommendation.

“The Governor-elect has been clear that PFAS contamination is a man-made catastrophe years in the making and anything less than an all-hands-on-deck approach to cleaning up our waterways is unacceptable,” according to the statement.

The science panel considered research in both toxicology and epidemiology to conclude that a lower health standard may be warranted, Savitz said. That approach allowed consideration of the family of chemicals and their makeup, as well as human health effects and diseases.

PFAS research historically focused on PFOS and PFOA, the chemical used for decades in consumer products like Teflon pans. It’s the research for PFOA, in particular, where the combined evidence “supports the potential for health effects resulting from long-term exposure to drinking water with concentrations below 70 ppt,” according to the report.

However, the scientists would not make a recommendation for a new health benchmark for lifetime PFAS consumption.

“Science does not provide a definitive answer to that question,” Savitz said. More likely will be a range where health effects could be better minimized based on available evidence that, over time, will become more apparent.

That creates confusion, he acknowledged, as various entities make their own guidelines. However, as the research builds toward clearer conclusions on PFAS, public policy needs to be able to follow in order to protect the most people.

“Information is evolving,” Savitz said, and that will help “reconcile scientific evidence and the kinds of decisions the state is facing now and will face into the future.”

Among other PFAS developments in the future will be technology to better address contamination clean-up, the scientists said, noting that destroying it by incineration is the best technique to keep it from remaining in the environment.

Researchers also expect to gain understanding on the spectrum of PFAS chemicals, which is one reason they consider PFAS as a class in this report instead of focusing on just PFOS and PFOA and the handful of other compounds that are increasing in public concern.

“Detection in the environment needs to consider the full spectrum,” Savitz said, “… to have a complete a look as we can.”

That includes considering the short-chain versions and precursor chemicals, or the related chemicals that remain in use in both industry and consumer products.

One consideration for Michigan – particularly its plating industry, which supports manufacturing – is how little information chemical companies provide about their products. That’s become an issue as the state identifies high levels of PFAS coming through its public wastewater treatment plants. An MLive investigation in November traced PFOS in levels about the regulated 12-ppt flowing into the plants from dozens of active businesses.

“The proprietary nature of the PFAS composition of products and goods in the marketplace is problematic for states like Michigan as it impedes the ability to monitor and plan mitigation of human exposure where needed,” the report said. “While concealing the identity of PFAS and other components in products may be important to protect intellectual property and patents, it is problematic when chemicals like PFAS end up in the environment, impacting soil, water, food quality, and ultimately the ecosystem and human health.”

The study also addresses that people may encounter multiple routes of exposure to PFAS, but concluded that drinking water is the most significant for public health. However, more research is warranted for many of those routes, including through food, air particles and skin contact, the researchers said.

Biomonitoring studies are recommended in the state to build more understanding of all PFAS and all of these routes, including quantifying which routes carry more risks.

That, in turn, will feed regulatory decision-making.

“I think we recognize this is not a process of looking at individual chemicals when there are hundreds or thousands (of them) involved, but we need an understating in a more systematic or global way,” Savitz said.

While the report makes 17 recommendations for Michigan, the application of the information “should be used as a model for other states as they begin to address this national problem,” wrote Snyder in an opening statement.

Snyder’s comment conveys some of the national issues with the contaminants: States largely are on their own to determine the presence of PFAS and the public health risks to their residents. At the same time, the Environmental Protection Agency has promised all year to release a PFAS management plan by the end of 2018. Experts, including Michigan leaders, say they hope the EPA addresses the chemicals as a class instead of individual compounds, and sets cleanup standards and an enforceable health advisory limit.

The report, said Savitz, a professor at Brown University, represents the independent opinions of the scientists – neither the opinion of their employers, nor the state. The other researchers on the project were:

As far as the rest of the year-long PFAS effort in Michigan, Isaacs said, the plan met its goals and “mitigated exposure to public health … from the most extensive public water testing in the nation.”

In addition to public water supplies, wells, public schools and wastewater plants, the testing touched airports – which have used fire-fighting foam containing PFAS. One example of progress, Isaacs said, “We will need to dispose of 37,000 gallons of PFAS.”

Isaacs concluded the presentation by announcing that she’d be retiring this week, a move that puts the leadership of MPART into the broad state government transition as Whitmer and a wave of newly elected officials take office in January.

The next logical step for Michigan, Isaacs said, is for legislators and the incoming administrators to review the report and MPART’s progress.

“They need to look at the appropriateness of setting a standard and understanding how standards are actually set,” Isaacs said.

State Rep. Winnie Brinks, D-Grand Rapids, introduced a bill in December 2017 to set a drinking water standard in Michigan for PFAS at 5-ppt. That never moved out of the Republican-controlled committee, something that she finds contradictory to the SB 1244 discussion - and the latest science report.

She said MPART has helped shed light on the scope of contamination in Michigan and “the entire effort is undermined" by the lame-duck proposal.

“My position has been that the legislature needs to pay attention to this and put a definitive limit on drinking water into statute," Brinks said, "and that’s just the beginning of what we need to do.”